The present invention generally relates to wireless communication networks, and particularly relates to networks that maintain dormant or inactive packet data sessions for mobile terminals.
Changes in the type of data accessed by users through wireless communication networks have changed the nature of call management. Not too many years ago, users of wireless communication networks used such networks primarily for voice call services. In this respect, wireless call management was similar to that used in the circuit-oriented world of wire line telephone service, albeit with special provisions for maximizing the number of users supported by a limited radio frequency spectrum.
In support of a voice call, a network typically allocates physical and logical resources to support the call. Physical resources might include RF transceivers at a radio base station and digital signal processors within a base station controller, while logical resources might include network transport channels for conveying call data and control information between various network entities. Even though some of these resources were shared, by time multiplexing with other users for example, many call processing resources conventionally remain dedicated to the user for the duration of the voice call.
This approach to resource management makes sense where the user's use of such resources is essentially continuous, as during a voice conversation. However, where the user only intermittently uses such resources, with potentially long idle periods between active periods, this approach entails significant inefficiencies. This type of intermittent usage characterizes the newer services offered by wireless communication networks.
Web browsing and other types of Internet-based activities, such as sending and receiving email, or receiving stock quotes, are by their very nature intermittent activities. Communication networks supporting packet data sessions use different call resource management techniques to capitalize on the intermittent nature of packet data communication. Networks based on the TIA/EIA/IS-2000 (IS-2000) family of standards exemplify contemporary wireless networks providing packet data services to users.
IS-2000 networks, as well as certain other types of networks, gain efficiency by de-allocating selected network resources during the dormant periods of a packet data session with a mobile terminal. Generally, the point-to-point protocol (PPP) connection is maintained over the dormant periods, but traffic channel and associated resources are released for use in supporting other mobile terminals. Thus, when the network receives data from an outside network, such as the Internet, it must buffer the data and then deliver it to the dormant mobile terminal after reactivation of that terminal.
Without effective control measures, buffering incoming data for dormant mobile terminals might overwhelm the network in terms of required storage space and signaling overhead associated with attempting to reactivate the involved mobile terminals. Thus, an approach that satisfies the requirements for buffering incoming data, yet manages buffering in a manner that limits the amount of buffer memory needed, and reduces reactivation signaling overhead is needed.